1. Field of the Invention
This invention relates generally to telephones on a common telephone line. More particularly, it relates to data communications between telephones on a common telephone line.
2. Background of Related Art
In the United States, Calling Identity Delivery (Caller ID) has become a popular service which provides call related information regarding a calling party to a called party before the called party answers the incoming telephone call. Typical call related information includes, e.g., a telephone number and/or a household name of the calling party.
Many conventional telephones include the capability to receive call related information regarding a calling party, e.g., common telephones, speakerphones, facsimile machines, and voice messaging systems, to name a few.
FIG. 4 depicts one type customer premises equipment capable of receiving call related information, i.e., a voice messaging system such as a telephone answering device.
A conventional telephone answering device generally operates on a single telephone line and answers an incoming call of a calling party to an unused (i.e., on-hook) telephone after a desired number of rings. Generally, a telephone answering device causes the telephone line to enter an off-hook condition, then plays an outgoing greeting message to the calling party. After the outgoing greeting message has played in its entirety, the calling party can typically leave a voice message on the telephone answering device. At a later time, the voice message is replayed by the user, depending on the features of the telephone answering device, either local to the telephone answering device or via remote connection from another telephone.
FIG. 4 illustrates the use of two (or more) conventional telephone devices connected to a common telephone line within a home or office 15. In the shown example, a telephone answering device 11 and a speakerphone 13 are each capable of answering an incoming telephone call to the telephone line.
The telephone answering device 11 is connected to a common telephone line 19 from a telephone company central office 17, as is the speakerphone 13. Both devices include an appropriate telephone line interface (TLI) 21, 23 to provides the conventional isolation, DC and AC impedance as required by local telephone company standards. The telephone line interfaces 21, 23 also provide a ring detect signal to a respective controller 25, 27. The controllers 25, 27 can be any suitable processor, e.g., a microprocessor, a microcontroller, or a digital signal processor (DSP). The ring detect signal indicates to the controller 25, 27 the ringing of an incoming call on the telephone line 19. The controllers 25, 27 may also include, e.g., in program code or in an external device, respective dual tone multi frequency (DTMF) generators 33, 35 and/or DTMF decoders 29, 31 to output and detect dialed digits of a telephone number. The DTMF decoders 29, 31 may also be used to detect control sequences from a remote telephone relating to specific features of the telephone answering device 11 or speakerphone 13.
The conventional telephone answering device 11 illustrated in FIG. 4 may also include a Calling Identity Delivery (Caller ID) detector/receiver 51 to detect and receive call related information, e.g., the telephone number and/or household name of a calling party. Typically, the received call related information is stored in non-volatile memory such as a Caller ID log 97. Current and past entries in the Caller ID log 97 may be displayed on a display 49 as selected through push button control by the user.
By using Caller ID, the user of the conventional telephone answering device 11 can determine the name and telephone number of the calling party leaving the voice message. Basic call information such as Caller ID information is transmitted from the local telephone company to the called party while the called party""s phone is in a hung-up or on-hook state, e.g., between the first and second rings.
Unfortunately, using conventional techniques, only one device on any one telephone line may communicate with the central office 17 to acknowledge receipt of call related information regarding an incoming call. Thus, only one device, e.g., the TAD 11 as shown in FIG. 4, may utilize a call related information detector/receiver 51. This may cause an inconvenience to the user, who may not be located within easy view of the display 49 of the one device (e.g., the telephone answering device 11), when the incoming telephone call arrives. Thus, the user must either not rely on the Caller ID capability of the distant device (e.g., the telephone answering device 11), or must run to the room containing the device including the Caller ID capability. Needless to say, this may at times be inconvenient for the user.
Accordingly, there exists a need for a telephone system which is capable of sharing call related information and other synchronizing data between multiple telephone devices within a home.
In accordance with the principles of the present invention, a customer premises equipment is capable of synchronizing data with other customer premises equipment. The customer premises equipment comprises a controller, a telephone line interface connectable to a common telephone line and in communication with the controller, and a call related information detector/receiver in communication with the controller. A data transfer module is in communication with the controller. The data transfer module is adapted to communicate with other customer premises equipment in communication with the common telephone line.
A method for sharing data between a plurality of telephone devices installed on a common telephone line in accordance with another aspect of the present invention comprises designating one of the plurality of telephone devices as a master telephone device, and the remaining one or more of the plurality of telephone devices as slave telephone devices. Data is transferred from the master telephone device to at least one of the slave telephone devices over the common telephone line.